Prof Xiang
Zhang

the spy's holy grail

The dream of “invisibility” has probably moved a
step closer after US scientists announce they have
crafted a material that can bend visible light
around objects.

Researchers at the University of California at
Berkeley, whose work is funded primarily by the
Pentagon, have engineered materials that can control
the direction of light.

The technology could lead to
systems for rendering anything from people to large
objects, such as aircraft or ships, invisible to the
naked eye. Its application in the world of espionage
and intelligence gathering are obvious. In 2006,
John Pendry of Imperial College London and David
Smith of Duke University in North Carolina used
microwaves to achieve similar results, yet according
to academics, achieving this effect using light is a
significant advance.

Above and below -
Tachi's projection project

Lead
scientist on the light project Xiang Zhang said: “In
the case of invisibility cloaks or shields, the
material would need to curve light waves completely
around the object like a flowing river around a
rock.”

HOLY
GRAIL OF ILLUSION ARTISTS

The search for “adaptive camouflage” as some
researchers refer to invisibility, has a long
history. In 1897, science fiction writer and author
of The Invisible Man, H G Wells, introduced the
idea, then fictional, of a scientific route to
invisibility through bleach and mysterious rays.

Some
would say today’s more modern experiments with
visual stealth have their roots in a 1943 US Navy
project code-named Yehudi. The purpose of this
programme, which was highly secret at the time and
came to light only in the 1980s, was to give Navy
patrol aircraft a better chance of sinking enemy
submarines. During 1942, German U-boats were a
constant menace of the eastern seaboard of the
United States and across the Atlantic. Hundreds of
merchant vessels were sunk. Though torpedo firing
aircraft were sent to sink the U-boats, they were
often spotted long before they arrived and the
submarines simply dived to safety.

The Yehudi team
needed a way to make the aircraft harder to see, and
camouflage paint alone wouldn’t do the job.
Regardless of what colour was used, the aeroplane
could be seen against the sky. Scientists believed
the only way to make them less visible was to
actually make the aircraft brighter by fitting
dozens of bright lights. At the time, this seemed
illogical to some military commanders.

Nevertheless,
engineers fitted a TBM-3D Avenger torpedo-bomber
with 10 sealed-beam lights installed along the wings
leading edges and the rim of the engine cowling.
When the intensity of the lights was adjusted to
match the sky, the Avenger blended into the
background. Tests revealed that the Yehudi system
lowered the visual acquisition range from 12 miles
down to two.

The British too worked mirrors, lights and other
systems, but the art of illusion, though fairly
successful in WWII and beyond, was never going to be
a permanent solution.

The search for “adaptive
camouflage” as some researchers refer to
invisibility, has a long history. In
1897, science fiction writer and author
of The Invisible Man, H G Wells,
introduced the idea, then fictional, of
a scientific route to invisibility
through bleach and mysterious rays.

Philadelphia Experiment
the official US Navy facts

Records in the Operational Archives
Branch of the Naval Historical Center
have been repeatedly searched, but no
documents have been located which
confirm the event, or any interest by
the Navy in attempting such an
achievement.

US Operational Archives
has reviewed the deck log and war diary
from USS Eldridge’s commissioning on 27
August 1943 at the New York Navy Yard
through December 1943. During this time
frame, Eldridge was never in
Philadelphia.

After many years of
searching, the staff of the Operational
Archives and independent researchers
have not located any official documents
that support the assertion that an
invisibility or teleportation experiment
involving a Navy ship occurred at
Philadelphia or any other location.